In recent years, a solar battery module has been attracting attention in view of effective use of resources and prevention of environmental contamination etc., because the solar battery module directly converts sunlight into electrical energy. In particular, since there has been increasing need for a lightweight and large-area solar battery module, development of such a solar battery module has been carried out.
For example, Patent Literature 1 discloses a solar battery module mounted on a sheet member. The solar battery module shown in Patent Literature 1 is described below with reference to FIGS. 12 and 13. FIG. 12 is a plan view illustrating (i) a sheet member 61 and a solar battery module 60 mounted on the sheet member 61. FIG. 13 is a cross-sectional view illustrating the solar battery module 60.
As illustrated in FIG. 12, the solar battery module 60 is sewed on the sheet member 61 with a thread 62. Further, as illustrated in FIG. 13, the solar battery module 60 is configured such that solar battery cells 65 are sealed within a sealing resin 66, which is sandwiched between a light receiving surface protection film 63 and a back surface protection film 64.
According to Patent Literature 1, a large-area solar battery module is formed by sewing a plurality of the foregoing solar battery modules 60 onto the sheet member 61. Note however that, while volume of the light receiving surface protection films 63 and the back surface protection films 64 with respect to volume of the large-area solar battery module is approximately 66%, volume of the sheet member 61 with respect to the volume of the large-area solar battery module is approximately 33%. Further, the sheet member 61 is greater in weight than the light receiving surface protection films 63 etc., because the sheet member is made from material with high mechanical strength. Accordingly, total weight of the large-area solar battery module is markedly large because of the sheet member 61.
On the other hand, there has been developed a large-area solar battery sheet that is constituted by a combination of flexible solar battery modules without a sheet member. For example, a conventional solar battery sheet array illustrated in FIG. 15 is described below. (a) of FIG. 15 is a plan view illustrating the solar battery sheet array. (b) of FIG. 15 is a cross-sectional view taken along line I-I′ of (a) of FIG. 15.
The solar battery sheet array illustrated in FIG. 15 is constituted by a plurality of unit solar battery sheets 110. FIG. 14 illustrates one of the plurality of unit solar battery sheets 110. (a) of FIG. 14 is a plan view illustrating one of the unit solar battery sheet. (b) of FIG. 14 is a cross-sectional view taken along line H-H′ of (a) of FIG. 14. The unit solar battery sheet 110 is configured such that (i) solar battery cells 104 are electrically connected in series with one another via inter connectors 105, and (ii) both ends of an electrical connection among the solar battery cells 104 are connected to respective bus sections 106a, which collect electric power.
Each of the bus sections 106a of the unit solar battery sheet 110 is protruded from a flexible resin film 101, a back surface protection member 102, and a silicon resin 103 so that the plurality of unit solar battery sheets 110 can be electrically connected with one another as illustrated in FIG. 15.
The solar battery sheet array shown in FIG. 15 is configured such that protruded parts of bus sections 106 of adjacent ones of the plurality of unit solar battery sheets 110 are welded together to form a welded part 107 and thereby the plurality of unit solar battery sheets 110 are electrically connected with one another via the welded parts 107. In addition, adjacent ones of the plurality of unit solar battery sheets 110 are physically connected with each other with use of an adhesive agent 108. The adhesive agent 108 fixes also a corresponding one of the welded parts 107, and has protection films 109 on its both surfaces.
According to the configuration as shown in FIG. 15, a large-area solar battery sheet array is formed without a sheet member. Therefore, with this configuration, it is possible to achieve a lightweight and large-area solar battery sheet array.